Amortizable Intangible Assets - Schedule of Carrying Amounts and Accumulated Amortization of Intangible Assets (Detail) - USD ($) $ in Millions |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Finite-Lived Intangible Assets [Line Items] | ||
| Gross Carrying Amount | $ 872.1 | $ 871.9 |
| Accumulated Amortization | (233.0) | (163.0) |
| Net Carrying Amount | 639.1 | 708.9 |
| Customer Relationships and Platforms [Member] | ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Gross Carrying Amount | 745.2 | 745.2 |
| Accumulated Amortization | (197.5) | (137.0) |
| Net Carrying Amount | 547.7 | 608.2 |
| Other [Member] | ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Gross Carrying Amount | 126.9 | 126.7 |
| Accumulated Amortization | (35.5) | (26.0) |
| Net Carrying Amount | $ 91.4 | $ 100.7 |